New regression formulas for sonographic weight estimation within 10, 7, and 3 days of delivery.
OBJECTIVE
The purpose of this study was to develop new regression formulas based on large numbers of sonographic examinations performed within 10, 7, and 3 days of delivery.


METHODS
Sonographic fetal biometric measurements and delivery ward data for an unselected population were analyzed. Multivariate linear regression models were fitted to the sonographic data to predict the actual birth weight (BW) within 10, 7, and 3 days.


RESULTS
The analyses included 6289, 5449, and 4007 patients who underwent sonographic examinations within 10, 7, and 3 days of delivery, respectively. All models yielded very high correlation coefficients (r = 0.927-0.958; R(2) = 0.859-0.918), low mean deviations between the calculated and actual BWs (6.4%-6.6% +/- 1 SD of 5.5%-5.9%), and high percentages of the calculated BW within 10% of the actual BW (78.5%-80.4%). Estimated fetal weight analyses made within 3 days of delivery yielded slightly better results than within 7 and 10 days.


CONCLUSIONS
The new regression formulas yielded overall similar results, with a small advantage for estimates calculated within 3 days of delivery. Further prospective studies are needed to compare the accuracy of these formulas with those used to date.
Ben-Haroush
Avi
A
Department of Obstetrics and Gynecology, Helen Schneider's Hospital for Women, Rabin Medical Center, 49100 Petach Tikva, Israel. yudavi@inter.net.il
Melamed
Nir
N
Mashiach
Reuven
R
Meizner
Israel
I
Yogev
Yariv
Y
D001699:Biometry / Q000379:methods*; D001724:Birth Weight; D003627:Data Interpretation, Statistical; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007231:Infant, Newborn; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*; D051598:Whole Body Imaging / Q000379:methods*